Blasting in Tunnel Construction

Drilling and blasting is the controlled use of explosives and other methods, such as gas pressure blasting pyrotechnics, to break rock for excavation. It is practiced most often in mining, quarrying and civil engineering such as dam, tunnel or road construction. Explosives for tunnel blasting can be either gelatine dy- ruwiite or ammonium nitrate. Detonation is accomplished by use of electric blasting caps with built-in delays.